1. Field of the Invention
This invention relates to a driving device used in an automatic seat belt system to move the seat belt between a seat occupant restraining position and a seat occupant liberating position.
2. Description of the Prior Art
A driving device is generally known in which a flexible drive member having one end attached to a rotatable member and the other end attached to a seat belt or a movable anchor or the like to which the seat belt is attached is taken up onto the rotatable member or pushed out therefrom to thereby move the seat belt in the automatic seat belt system between a seat occupant restraining position and a seat occupant liberating position. However, in the driving device according to the prior art, the entrance and exit for the drive member formed in a frame member provided in a stationary state relative to the rotatable member lies in the same plane as the drive member taking-up space portion of the rotatable member with respect to the direction of the rotational axis of the rotatable member. Accordingly, the drive member which tends to be inflated radially outwardly when pushed out from the rotatable member is strongly urged against the wall surface of the frame member which lies in the same plane over a considerable range to the exit and even if the rotatable member rotates to try to push out the drive member, a situation in which the drive member is not smoothly pushed out from the exit due to the frictional action with said wall surface is liable to occur. Also, a situation in which a frictional action interacts between a plurality of turns of the drive member, whereby the drive member fails to be smoothly pushed out from the exit is liable to occur.